My Cloud FirmwareOperating system · Westerndigital

CVE-2020-27159

CRITICAL · 9.8 CVSS v3.1 Published 2020-10-27
Fix available
A fix is available. Upgrade to 5.04.114 or later.
See remediation →
100/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Addressed remote code execution vulnerability in DsdkProxy.php due to insufficient sanitization and insufficient validation of user input in Western Digital My Cloud NAS devices prior to 5.04.114

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-78

User input reaches a shell or system command without being fully separated from the command itself, so an attacker can append their own instructions. Because these run with the application's privileges, it often means full control of the host. The lasting fix is to avoid the shell entirely — call APIs directly and pass arguments as data, never as concatenated strings.

General guidance for the os command injection class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
My Cloud FirmwareOperating system
Affected:< 5.04.114

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 5.04.114 or later
Fixed in 5.04.114
Recommended fix High confidence

My Cloud Firmware version 5.04.114 or later

  1. 1. Back up all critical data on the My Cloud device to an external location before proceeding with the firmware update
  2. 2. Visit the official Western Digital support website at www.westerndigital.com and navigate to the My Cloud product support page
  3. 3. Locate and download the firmware version 5.04.114 or later for your specific My Cloud model
  4. 4. Log in to the My Cloud web interface (typically at http://mycloud.local or the device's IP address) with administrator credentials
  5. 5. Navigate to Settings > Firmware Update or Settings > Administration > Firmware Update
  6. 6. Select the option to upload the downloaded firmware file and initiate the update process
  7. 7. Wait for the firmware upload and installation to complete - do not power off the device during this process
  8. 8. The device will automatically restart after the update completes
Caveat Firmware updates typically preserve settings, but a factory reset may be required if issues arise; backup configuration before updating

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $3,550. Get the upgrade done

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2020-27159 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2020-27159 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data